Focal plane shutter control



May 30, 1944. c. c, FUERST FOCAL PLANE SHUTTER CONTROL Filed July 17, 1942 v 2 Sheets-Sheet l VIII/III I CARL C. FUERS T INVENTOR BY MZIZW ATTORNEYS May 30, 1944. Q Q FUERST 2,350,026

FOCAL-PLANE SHUTTER CONTROL Filed July 17, 1942 2 Sheets-Sheet 2 FIG 6, FIGQQ.

FIG. 7. q 16 FIG 10 L 2- i *W2 I i 49 @o 1 EL 7 6 J6 CARL c. FUERST INVE TOR A? 40 W BY A TIORNE YS Patented May 30, 1944 FOCAL PLANE SHUTTER CONTROL Carl C. Fuel-st, Rochester, N. 1., asaltnor to Eastman Kodak Company, Rochester poratlon of New Jersey Application July 1'1, 1942, Serial No. 451,277

12 Claims.

This invention relates to photography and more particularly to a control mechanism for a focal plane shutter. one object of my invention is to provide a shutter control which may adJust the shutter cln'tains in such a way that variously timed exposures may be obtained. Another ob-- ject of my invention is to provide a shutter mechanism by which the duration of the exposure can be adjusted either before or after an exposure has been made. Another object of my invention is to provide a' focal plane shutter control which is cwiparatively simple and which consists of relatively few simple parts. Other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

In the past most focal plane shutters have been provided with a mechanism with which the shutter aperture or the time controlling mechanism can be set when the shutter parts are in one position. Usually this position is the run-down position which the curtains assume after an exposure has been made. In most shutters a stop can be moved so that upon rewinding the shutter to condition it for an exposure the stop will determine the slot between the curtain sections and consequently the exposure. with this type of shutter the difficulty frequently arises that an operator may wish to vary the exposure after having wound the shutter. It is then necessary to protect the film against light and permit the shutter to run down and then again set the mechanism determining the shutter speed or else to use the speed for which the shutter has already been set.

In other known types of shutters it is possible to set the focal plane shutters either before or after exposure, but in most shutters of this type the mechanism is far more complicated since they usually include some clutching mechanism which requires a separate operation on the part of an operator to properly set the shutter. It is an object of my present invention to provide a focal plane shutter with an extremely simple type of control and one which requires no additional operation on the part of the operator to set the shutter regardless of the position in which the shutter curtains may be located.

Coming now to the drawings wherein like reference characters denote like parts throughout:

Fix. 1 is a fragmentary view partially in elevation and partially in section showing a'shutter control mechanism constructed in accordance with and embodying a preferred form of my invention;

, N. Y., a corline 2-1 of Fig. 1 P rts being shown in elevav tlon;

Fig. 3 is a fragmentary detail section taken on line 3-3 of Fig. 1;

Fig. 4 is a fragmentary detail section through the shutter setting mechanism;

Figs. 5, 6 and 7 are plan views partially in section showing the relationship of the setting disk and of the curtain disk in various different positions;

Figs. 8, 9 and 10 are schematic views showing the relationship of the curtains to the exposure aperture when the curtains are in different positions;

Fig. 11 is a, fragmentary view partially in elevation showing the bulb lever in a position to produce'a bulb exposure; and

Fig, 12 is a sectional view through a curtain supporting roller.

My invention relates to a shutter of the type employing two curtains each mounted at one end on its own individual spring roller and each mounted at its other end on a rotatable type of support, the two curtains being moved together to make an exposure of the instantaneous type or of the bulb" type. My invention is particularly directed to the shutter control mechanism for adlusting the two shutter ends to produce slots of varying widths between the curtains in order to obtain different exposures.

More specifically, my shutter may comprise a support B which may be either a shutter housing or it may bea camera body in which the shutter is mounted. The shutter may consist of a pair of curtains, a leader curtain i and a follower curtain 2. The leader curtain may be attached to a spring driven roller 3 and the follower curtain may be attached to a spring driven roller 4 in a known manner. The curtain i may pass over guiding spools i in its path to its roller 3 r so that it will clear the roller 4 on which the curtain I may be wound. The rollers 3 and 4 are provided with springs s which always tend to turn these rollers in the direction shown by the arrows to wind the curtain thereon.

The curtain I may be provided with suitable tapes 6 which may be wound on similar spools I mounted on each side of a drum I and carried by a shaft 0 to which the rollers may be pinned as at Ill. The upper roller I includes a collar ii on the end of which is a gear i2 meshing with a second gear I: mounted to rotate freely on a shaft I4 and meshing with a gear i5 which may be considered as a curtain disk.

Fig. 2 is a fragmentary sectional view taken on The follower t n I may be connected y shaft 9 and carries a The drum 8 is mounted to rotate freely on thegear attached to a collar 2I so that this gear may rotate with the drum 8. The gear 20 may mesh with a gear 22 carried by the collar 2: which meshing with a gear 25. v

The gears I! and 25 may turn freely on the stud shaft 26 mounted on a mechanism plate 21. Also on this shaft is a gear 28 which is the prime mover, this gear being turned to set the shutter curtains I and 2 in a manner to be hereinafter more fully described. The gear 28 may be driven by any suitable mechanism, either by hand or by power, but it ma lie idle upon the shaft 28 except at such times as it may turn to set the shutter members.

The gear 28 is provided with a single-toothed ratchet 29 with which a pawl 30, pivoted at 3| to the gear 25, may cooperate. This pawl has an arm or extension 32 which, when the shutter is in a set position, lies in the path of the arm I: of

a trigger member 24 pivoted at 35 to the support B and having a spring 36 positioned to hold the parts in position shown in Fig. 1. When the trigger 34 is moved in the direction shown by the arrow, the one-toothed ratchet 29 is released so that the shutter may run down.

For instantaneous exposures the curtains I and 2 are adjusted so that the width W of a slot between these two curtains will determine the exposure. In other words, when the curtains are wound up and a slot W has been established,

the release of the trigger 34 will c use the slot the exposure aperture A and W to cross over make an exposure. ing operations will exposure.

Repeated setting and releascontinue to make the same of the curtains I and 2 are changed. For inthe two curtains with the width W of the slot between the two curtain edges an extremely large one, such a setting being used for relatively slow exposm'es, such second. This is also used for Fig. 10 shows the width of the slot W as being quite a narrow one, such as would produce a Imoo of a second exposure. These indicate two extreme exposures of the instantaneous type and of course, by positioning the two shutter curtains in various positions between -W and W, exposures of various diflerent times may be obtained. The mechanism for obtaining the various settings includes a shutter setting disk 40, as shown in Fig. 4, this disk preferably having graduations on its upper surface 4| which may be viewed through the window 42 of the support B to indicate the particular setting. The disk 44 is mounted on a shaft 43 slidably mounted in the support B and terminating in a setting knob 44 normally springpressed upwardly by a spring 46 so that a pin 46 may enter any one of a series of apertures {41 positioned for various difierent shutter settings.

The setting disk 48, best shown in in the path of a cooperating stop pin 49 caris provided with a stop pin vice, the other also supports a gear 24 I 'rIed by the curtain disk or gear I5. The disc 4| likewise i provided with a second pin BI which constitutes one member of a coupling demember of which is an aperture 5| which is drilled in the stop pin 49 so that it may receive' the coupling member 50 carried by the disc when the knob 44 is moved against the pressure of spring into the position shownin Fig. 4. Thus, the curtain disk or gear I5 is provid'ed with both a stop pin and a coupling member, which in this instance may be made in one piece.

In order to set the shutter the knob 44 is I moved downwardly to release the pin 46 from Fig. 3, this stop Din lyin 1 .window 42.

an aperture 41 and it 'is then turned until the required time may appear through the window 42. This may be done at any time. If the shutter has 'just made an exposure and the setting knob 44 is turned, it will merely position the stop pin 48 so that, when the prime mover or gear 28 is moved to wind the shutter, both ourtains will be turned by the prime mover into a position in which the springs S in the rollers 3 and 4 will be placed under tension. This movement occurs since the gear 25 is turned through the pawl 30 and' ratchet tooth 29 and since this gear 25 transmits motion to the gear ii to a slip clutch including spring members carried by a ratchet wheel 6|, the teeth of which may be engaged by a pawl 62 spring pressed into engagement with the teeth by a spring 63. Thus, the gear 25 will turn approximately one revolution in winding up the distance that the shutter I will move will be controlled by the position of the stop pin 48, since the gear I5 will be turned through the slip clutch 60 only until the pin 49 strikes 1 the pin 48 as indicated in Fig. trol the width W of the slot between the 'curtain members but the extent of movement of the curtain members is such that the curtain I will always be moved until the aperture A, through which exposures are made, is completely covered.

Thus, if the knob 44 has been turned for a required exposure when the shutter is run down, the action above described will take place. However, if the shutter has been wound, by turning the prime moving gear 28 as above described, and the operator should decide that he wishes to again alter the width of the slot W to produce a difierent exposure, this may still be done by means of the coupling operator is not conscious of any difierent setting operation, since, as before, he merely presses downwardly upon the knob 44 to turn the setting disk 40 until the proper indicating mark on the surface 4I of the disk'appears below the But if the shutter has been tensioned the stop pins 48 and 49 are located as shown in Fig. 3 so that the downward pressure upon the knob 44 engages the coupling members 50, 5| and positively unites the. setting disk H with the shutter disk or gear I5. When so coupled they may 'be moved together by turning the knob 44 as the clutch member 60 slips. Thus they may be turned to any desired position and when the time or width of the slot has been selected the knob 40 is permitted to rest under the impulse of its spring 45 causing the pin 48 to enter a locating aperture 41. When this is done, the coupling members 50, 5| become 3. This will condisenaaged and an exposure may proceed as bethe shutter 2, whereas members 50, 5|. The' coupling member.

In order to obtain prolonged exposures or ex-' posures commonly called "bulb" exposures, I provide a separate mechanism which will act to hold the second shutter against movement when the trigger is depressed and until the trigger is released at which time the shutter aperture A will be closed-by the second shutter. As shown in Figs. 1 and 11, the bulb mechanism includes a lever I63, pivoted at III to the mechanism plate, and pressed by a spring I" in the direction shown by the arrow, Fig.,11, so as to hold a pin I63 either against the periphery 34 or the setting disk 40, or to cause the pin to drop into a notch 65 when the shutter setting disk is moved to its '"bulb" position. In this position a stop 66 carried by arm 31 of the lever is brought into the path of a stop lug 33 which is carried by gear 25, and which is so positioned on the gear that the shutter 2 may be held against movement and uncovering the aperture A while the shutter I which is already across the aperture A is -also held still. As long as the stop ing 68 and lever 33 are in the position shown in Fig. 6, the shutter remainsopen. when the trigger 34 is moved its spring 36 is released so that the trigger moves pin I63 from the notch 85 so that the shutter may close.

When a bulb exposure is to be made the trig- I ger 34 is moved so as to release the lever 33 path of the stop pin 43 so that, when the shutter is turned for winding the curtain springs, curtain 3 will be completely wound through its gearing 23, 24, 23 and gear 23 and curtain I will be turned through its gearing I3, I3 and gear I2,

and will-be permitted to turn only until the stop permitting the first shutter member to .move

across the exposure aperture A and permitting the shutter ,2 to move onl until lug 83 strikes lug 66, in which position the edge of the curtain 2 will lie adjacent the edge of the exposure aperture A with the exposure aperture A completely uncovered. Both curtains then stop since theymove in unison in making an exposure. By

this lever to move in the direction opposite to that shown by the arrow in Fig. 1 and such movement causes the arm 33 to lift arm 31 of the bulb lever out 0! the depression I in the releasing the trigger 34 the spring 33 will cause disk 40 and out of the path oi the stop lug 88.

This permits the shutter curtains i and 2 to move under the impulse of their springs in rollers 3 and 4 to cover the exposure aperture A.

If the knob 44 is turned until the pin I63 rides on the periphery 64 oi the shutter setting disk 43, the lug 66 will be held out of the path of the lug 68 as in Fig. l. The stop lever is held in this position for all exposures except the bulb exposure which can occur only when the notch 35 is brought in position to receive the pin I33 as indicated in Fig. 11.

The operation of this shutter is extremely simple. If an operator wishes to make a licenseeond exposure, he merely presses the knob 44 and turns the disk 40 until the proper graduation appears through the window 42. This operation may take place regardless of the locational the shutter curtains. If the shutter curtains have been wound by turning the prime mover 23, the stop pins 48 and 43 are in the position shown in Fig. 3 in which they locate the coupling members pin 43 strikes the stop pin 44. This turning movement is always sufllcient to completely close the aperture A, but it is not suflicient to close up the slot W between the two ends of the curtain members I and I.

Thus I have provided a simple shutter adjusting mechanism which operates in two distinctly diil'erentmanners, one when the shutter is set and the other when the shutter is unwound. Either of these two modes of operation of the mechanism does not require any extra operations by the operator because in one case he merely sets a stop pin in a position to adjust the shutter slot while the curtainsare being wound, and in the other position the stop pins have properly located coupling members so that they will be automatically coupled and will permit the operator to adjust the width of a slot between the wound curtains. In either'case, as far as the operator is concerned, the same steps are taken in setting the shutter,

It is obvious that, while I have described a preferred embodiment of my invention, other embodiments may be madewithout departing from my invention. I consider as within the scope of my invention all such forms as may come within the scope of the appended claims.

I claim: K

i. In a focal plane shutter of the type employing two curtains each mounted on an individual constituting a curtain disk movable with ashutter curtain, cooperating stops one on each disk whereby movement 01' the curtain disk maybe limited, and a pair of coupling members, one carried by the setting disk and the other carried by the curtain disk, a mount on which the setting disk may move axially to engage the coupling members when properly positioned for turning the curtain disk from the setting disk for ad- 50, if so that, by depressing the knob the coupling members temporarily unite the setting disk 43 and the curtain disk I5 so that they may be moved together as the clutch 63 slips and until the'desired speed appears in the window 42. If, on the other hand, the shutter has not been set by turning the knob 44 as above described the stop pin will merely be placed somewhere in the 'justing one curtain relatively to the other.

2.- In a focal plane shutter of the type employing two curtains each mounted on an individual spring roller at one end and on separate rotatable supports at the other end and means for providing predetermined widths of slot between the ends of the curtains to produce different exposures, the combination with said means for providing ,predetermined widths of slot for exposures, of a control therefor including a pair of separately rotatable disks,- one of said disks constituting a setting disk, the other of said disks constituting a curtain disk movable with a shutter curtain, cooperating stops one on each disk whereby movement of the curtain disk may be limited, and a pair of coupling members, one carried by the setting disk and the other carried by the curtain disk, a mount on which the setting disk may move axially to engage the coupling members when properly positioned for turning the curtain disk from the setting disk for adjustone curtain relatively to the other and means for! holding? =thersettingfdiskz, ineae predetermined position' operabieiwvhen'r'said -settingdisk moves x'ially to release saidrcouplingamembers. 3. .vIna-docalplaneshutter oi? the type employin: twoscurtain's eachremountede-onanindividual rspring roller.-;at.-:one;send and on-iseparate rotat- ;ablearsupportsgtat rthe eothereend'eand means for aeprovidingeipredetermmedwwidthsgof slot between aothe ends-yofJthe curtains.itosproduce.:diiierent exa@posuresmthexcombinationswith saidmeans for providing predetermined-widths of =slot for exersvwhenwprop rly 1 positioned .for turning the curtain disk; fromthe settingdisk for adjust- ;ing necurtain relatively to the other, said co- 1; ,operating stopsgcn the -shutter'disk and curtain ,disk belngso located-relative to the stop pins that said coupling members maybe automatically engaged by moving the setting disk axially ,whenthe cooperatingstop pins are in engagementaftersettingvthe shutter,- and means for- -setting the-shutter comprising mechanism for ysimultaneolislywinding-both curtains.

4. In a focalpiane shutterof the type employing two curtains each-mounted on an individual spring roller, at one, end and on separate rotatable supports atthe-otherend and means for providing'predetermined widths of slot between the ends of the curtains to produce difl'erent exposures,.,.the combination wih said means for providing predetermined widths of slot for ext posures, of a control therefor including a pair of separately rotatable disks, one of said disks constituting a setting disk, the other'oi said disks constituting a curtain disk movable with a shutter curtain, cooperating stops, one on each disk 7 whereby movement of the curtain disk may be limited, andha pair of coupling members, one

[carried by the setting d k and the other carried by the curtain disk, a mount on which the settingdisk may move axially to enga e the coupiing members when, properly positioned for 'turningthe curtain. disk from the setting disk for adjusting onecurtain relatively to the other, ""saidecooperating stepson the. shutter disk and curtain, disk, means for winding the shutter members together including a driving element, a

, driven element fand a friction clutch between one curtain and the driving element, saidcooperating .s'tops on' the shutter and setting disks engagedinsetting the shutter, and

coupling members, carried by the shutter and v settingdisks positioned to automatically engage by moving said settingdisk' axially when said '0 peratingv stcpsare in-curtain winding eneagement.

gearing and the winding member whereby said curtains may move together or separately. direct connections between the winding member and one curtain, indirect connections through the friction clutch between the winding member and the other curtain, a curtain disk and stop pin movable with the second curtain, a setting disk and stop pin coaxialiy arranged with the curtain disk 'whereby the setting ofthe setting disk stop pin may limit the winding movement or one shutter curtain, and a pair or coupling members carried by the setting and curtain disks and adapted to be positioned for engagement when the stop pin come into engagement.

6. In a focal plane shutter of the type including two curtains each mounted at one end on individual spring rollers and at the other end on 15. In a focal plane shutter of the type including twocurtains each mounted atone end on individual spring rollers fund at the other end on separately rotatable supports, the combination with said curtains, of mechanism for winding *saidcurtains to tension their spring rollers including-gearing connecting the separately rotatable suppor a winding member, a pawl and .ratchet and frictionclutch between the curtain separately rotatable supports, the combination with said curtains, of mechanism for winding said curtains to tension their spring rollers including gearing connecting the separately rotatable supports, a winding member, a pawl and ratchet and friction clutch between the curtain gearing and the winding member whereby said curtains may move together or separately, direct connections between the winding member and one curtain, indirect connections through the friction clutch between the winding member and the other curtain, a curtain disk and stop pin movable with the second curtain, a setting'disk and stop pin coaxialiy arranged with the curtain disk wherebythe setting of the setting disk stop pin may limit the winding movement of one shut ter curtain, and a pair of coupling members carried by the setting and curtain disks and adapted to be positioned for engagement when the stop pins come into engagement, whereby a slot 01' a predetermined width may be formed between the curtains, and means operable after windingthe shutter curtains to a set position for opening or closing the-shutter slot so formed. r

'I. In a focal plane shutter of the type including two curtains each mounted at one end on individual spring rollers and at the other end on separately rotatable supports, the combination with said curtains, of mechanism for winding said curtains to tension their spring. rollers'including gearing connecting the separately rotatable supports, a winding member, a pawl and ratchet and friction clutch between the curtain gearing and the winding member whereby said curtains may move together or separately, direct connections between the winding member and one curtain, indirect connections through the friction clutch between the winding member and the other curtain, a curtain disk and stop pin movable with the second curtain, a setting disk and stop pin coaxially arranged with the curtain disk wherebythe setting of the setting disk stop pin may limit the winding movement of one shutter curtain, and a pair of coupling members carpins come into engagement, whereby a slot of a predetermined width may be formed between the curtains, and means operable after winding the shutter curtains to a set position for opening or closing the shutter slot so formed, and comprising a positive coupling between the setting disk and the shutter disk for altering the width of the slot formed between the curtains.

8. In a focal plane shutter of the type including two curtains each mounted at one end on individual spring rollers and at the other end on separately rotatable supports, the combination 2,sso,oac

with said curtains, of mechanism ior winding said curtains to tension their spring rollers including gearing connecting the separately rotatable supports, a setting disk including a notch in its periphery, a curtain stop lever pivotally mounted adjacent said setting 'diskand including a pin resting on the periphery oi the setting disk and adapted to drop into the notch therein, gearing mpvable with the second curtain, a stop pin carried by said gearincluded in said gearing positioned to swing through a path, the end said stop lever intersecting said path for holding said curtain in an open position when the pin rests in the notch and the stop pin and lever engage, and a trigger member for releasing the stop pin by moving the stop lever from the notch in said setting disk.

9. In a focal plane shutter oi the type including two curtains each mounted at one end on individual spring rollers and at the other end on separately rotatable supports, the combination with said curtains, of mechanism for winding said curtains to tension their spring rollers including gearing connecting the separately rotatable supports, a setting disc including a notch in its periphery, a curtain stop lever pivotally mounted adjacent said setting disk and including a pin resting on the periphery of thesetting disk and adapted to drop into the notch therein, gear ing movable with the second curtain, a stop pin carried by said gear included in said gearing D sitioned to swing through a path, the end 01' said stop lever intersecting said path for holding said curtain in an open position when the pin rests in the notch .and the stop pin and lever engage, and a trigger member for releasing the stop pin by moving the stop lever from the notch in said setting disk, a latch for releasing the first curtain, said trigger being positioned to move the curtain latch when moved in on'edirection.

10. In a focal plane shutter oi the type including two curtains each mounted at one end on individual spring rollers and at the other end on separately rotatable supports, the combination with said curtains. oi mechanism for winding said curtains to tension their spring rollers including gearing connecting the separately rotatabl upports, a setting disc including a notch in its periphery, a curtain stcp lever pivotally mounted adjacent said setting disk and including a pin resting on the periphery oi the setting disk and I s tain, said trigger being positioned to move the curtain latch when moved in one direction, and to move the stop lever releasing the'other curtain when moved in a reverse direction.

11. In a. focal plane shutter oi the type including two curtains each mounted at one end on individual spring rollers and at the other end on separately rotatable supports, the combination with said curtains, of mechanism for winding said curtains to tension their spring rollers including gearing connecting the separately rotatable supports, a setting disk including a notch in its D riphery, a curtain stop lever pivotally mounted adjacent said setting disk and including a pin resting on the periphery oi! the setting disk and adapted to drop into the notch therein, gearing movable with the second curtain, a stop pin carried by said gear included in said gearing positioned to swing through a path, the end oi said stop lever intersecting said path ior holding said curtain in an open position when the pin rests in the notch and the stop pin and lever engage,

and a trigger member for releasing the stop pin by moving the stop lever from the notch in said setting disk, a latch for releasing the first curtain, said trigger being positioned to move the curtain latch when moved in one direction, and to move the stop lever releasing the other curtain when moved in-a reverse direction, a setting handle carried by the setting disk and a pin and aperture means for holding the setting disk in a set position whereby the said step lever may be moved to or from an operative position in which it may engage the notch in the setting disk.

12. In a focal plane shutter oi the type including two curtains each mounted at one end on inadaptedtodropintothenotchthereimgearin'gmovablewiththesecondcurtaimastoppincarried by said ge'ar included in said gearing 9 itionedtoswingtbroughapamthe endoisaid stop lever intersecting said path for holding said curtaininanopenpositionwhenthepinrests in thenotchandthestoppinandleverengage,

and a trigger member tor releasing by moving the stop lever from the setting disk, a latch for releasing the dividual spring rollers and at the other end on separately rotatable supports, the combination with said curtains, of mechanism for winding said curtains to tension their spring rollers including gearingconnecting the separately rotatable supports, a setting disk inciuding'a notch in its periphery, a curtain stop lever pivotally mounted adjacent said setting disk and including a pin resting on the periphery of the setting disk and adapted to drop into the notch therein, gearing movable with'the second curtain, a stop pin carried by said gear included in said gearing positioned to swingthrough a path, the end of said step lever intersecting said path for holding said curtain in an open position when the pin rests in the notch and the stop pin and lever engage, and a trigger member for releasing the stop pin by moving the stop lever from the notch in said setting disk, the shape or the periphery of the setting diskbeing such that the curtain stop levermaybeheldout'otthepathofthestcppin carried by said gear except at such times as the lever may be positioned by the notch in the periphery oi the disk.

CARL C. I'UIRST. 

